In general, a power transmission/distribution wire or a power supply system similar thereto senses only whether a voltage or current is abnormal, by the installation of a potential transformer or current transformer on the secondary side of a transformer in order to sense an abnormal current or check the current power transmission/distribution state. Also, in the case of a high voltage, sensing only whether a current flowing at a metering out fit (MOF) terminal is abnormal and transmitting it wirelessly are partially applied to sites.
However, the above-described current transformer has the following limitations.
Firstly, since current sensing CT used as a sensor is not suitable for charging a battery, there is a need to use a battery used as a main power source. To this end, there is an attempt to use a portion of the current sensing CT but it causes the interference between the core of a power generating CT and the core of a current sensing CT.
Secondly, there is an attempt to form the core of the power generating CT and the core of the current sensing CT separately to prevent electrical interference. However, since such a case also employs coupling two cores to a single structure, there are many limitations in simultaneously coupling without a gap when the two separable cores are installed at a wire.
Thirdly, when the above-described magnetic structure is demolished in order to change the installation section of the current sensing CT, it is difficult to separate a magnetic core based structure with a physical force when a wire current is equal to or higher than a certain level, thus maintenance is difficult. In particular, when used for the power generating CT, there is a limitation in that there is a need to interrupt a current on a typical wire when the structure is demolished.
Fourthly, since the main function of the above methods is sensing an abnormal current, there is a limitation in monitoring a wire current and a voltage state in addition to the abnormal current in real time.